The invention relates to erasable inks for use on marker boards.
Marker boards, or "whiteboards", are writing boards which can be used in combination with a pen, instead of chalk, and erased using, e.g., a tissue or soft cloth. These boards typically are plastic or ceramic, and have a smooth, hard, glossy surface.
Erasable inks having specialized properties are required for use with marker boards. It is important that the ink be able to wet the glossy surface, that the ink dry relatively quickly, and that the dried ink be erasable with a tissue, soft cloth or felt eraser. Other desirable properties include minimal shrinkage of the ink during drying, erasability after a period of time, and minimal residue left on the board after erasing. It is also desirable that the ink be suitable for use on most or all types of marker boards, a requirement which is difficult to meet due to the different surface properties of different marker board materials.
Marker board inks are described, e.g., in U.S. Pat. Nos. 3,834,823, 3,949,132 and 4,935,461.